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/*
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  SD card read/write
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 This example shows how to read and write data to and from an SD card file 	
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 The circuit:
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 * SD card attached to SPI bus as follows:
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 ** MOSI - pin 11
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 ** MISO - pin 12
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 ** CLK - pin 13
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 ** CS - pin 4
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 created   Nov 2010
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 by David A. Mellis
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 updated 2 Dec 2010
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 by Tom Igoe
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 This example code is in the public domain.
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 */
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#include <SD.h>
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File myFile;
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void setup()
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{
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  Serial.begin(9600);
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  Serial.print("Initializing SD card...");
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  // On the Ethernet Shield, CS is pin 4. It's set as an output by default.
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  // Note that even if it's not used as the CS pin, the hardware SS pin 
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  // (10 on most Arduino boards, 53 on the Mega) must be left as an output 
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  // or the SD library functions will not work. 
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   pinMode(10, OUTPUT);
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  if (!SD.begin(4)) {
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    Serial.println("initialization failed!");
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    return;
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  }
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  Serial.println("initialization done.");
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  // open the file. note that only one file can be open at a time,
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  // so you have to close this one before opening another.
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  myFile = SD.open("test.txt", FILE_WRITE);
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  // if the file opened okay, write to it:
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  if (myFile) {
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    Serial.print("Writing to test.txt...");
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    myFile.println("testing 1, 2, 3.");
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	// close the file:
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    myFile.close();
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    Serial.println("done.");
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  } else {
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    // if the file didn't open, print an error:
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    Serial.println("error opening test.txt");
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  }
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  // re-open the file for reading:
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  myFile = SD.open("test.txt");
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  if (myFile) {
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    Serial.println("test.txt:");
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    // read from the file until there's nothing else in it:
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    while (myFile.available()) {
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    	Serial.write(myFile.read());
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    }
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    // close the file:
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    myFile.close();
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  } else {
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  	// if the file didn't open, print an error:
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    Serial.println("error opening test.txt");
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  }
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}
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void loop()
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{
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	// nothing happens after setup
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}
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